1. Field of Invention
The present invention relates to a method of fabricating antibacterial fibers. More particularly, the present invention relates to a wet spinning method of fabricating nano-silver fibers.
2. Description of Related Art
As living standards have increased, antibacterial requirements for sanitary articles, daily-use articles, water treatment apparatuses, and food packaging have also increased. Therefore, adding antibacterial agents in these articles and apparatuses have become increasingly more welcomed by consumers. Among the applications, the earliest application of antibacterial textiles was during the Second World War. The percentage of injured persons becoming infected was thus largely decreased.
The commonly used spinning method can be divided into three classes: melt spinning, dry spinning and wet spinning. Wet spinning can be easily performed at a relatively low temperature and hence is quite economic. Therefore, wet spinning is widely used to fabricate acrylic fibers and Rayon fibers. If wet spinning could be used to fabricate antibacterial fibers, a large profitability could be obtained.
There are some methods of fabricating antibacterial fibers by wet spinning developed in the prior arts. For example, in U.S. Pat. No. 6,524,505, chitosan is used as an antibacterial agent. The chitosan is dissolved in water first. After processing acrylonitrile polymer to form acrylic fibers, the acrylic fibers are immersed in the aqueous solution of chitosan to allow chitosan to coat on the acrylic fibers.
In U.S. Pat. No. 6,685,957, an antibacterial agent with bioactivity is dissolved in water. The aqueous solution of the antibacterial agent is added to an organic phase of a spinning solution to form an emulsion. The emulsion is flowed out from outlets of a spinning apparatus into a water tank to form antibacterial fibers.
In Japan Publication No. 09-059820, titanium dioxide is used as an antibacterial agent. Titanium dioxide powder is dispersed in an organic solvent to form a suspension solution. The suspension solution is mixed with an organic solution of acrylonitrile copolymer. Then, wet spinning is performed to get antibacterial fibers.
As with the descriptions above, wet spinning is performed after mixing an antibacterial agent and a spinning solution in most prior arts. However, either the particle size of the antibacterial agent is too large or it is difficult for the antibacterial agent to disperse in the spinning solution. Therefore, the antibacterial agent cannot be dispersed in the spinning solution uniformly. This usually requires the amount of the antibacterial agent added to the spinning solution to be multiple weight percents to enable the obtained fibers to have antibacterial ability. Moreover, the obtained antibacterial fibers are not water-wash resistant. Consequently, the antibacterial ability of the obtained antibacterial fibers is largely decreased after washing with water.